A BEHEMOTH of bygone Irish industry is buried amidst meadows and woodland about 15 kilometres from Cork city.
The remaining structures of the Gunpowder Mills can be found scattered throughout the 130 acres of Ballincollig Regional Park. Often hidden within thick vegetation, various buildings can appear unexpectedly as you stroll through the woods.
In the late 18th century, the chemical processing industry experienced a boom in Cork, with various productions being established, including that of gunpowder.
Dublin was the centre of the explosives industry until the Gunpowder Mills in Ballincollig shifted the balance, and between 1794 and 1815 the mills were the largest in Ireland and one of the largest in the former United Kingdom.
Charles Henry Leslie, who was a Cork banker, established the mills along with John Travers in 1794. In that year they constructed the original Inniscarra weir and laid the plans for the mills.
Good access to the port of Cork was a determining factor in the choice of site, as large volumes of gunpowder were set to be supplied and transported for the needs of the government. Other engineering factors were also pivotal, such as adequate isolation and size. This was necessary in order to manage the hazardous processes that were carried out.
A constant supply of water was imperative to provide the energy required to power the machinery.
As you walk around the Gunpowder Mills, you’ll notice how spaced out the buildings are. This was a key design feature to decrease the chances of dangerous chain-reaction explosions, which would have seen the destruction of many buildings, rather than just one.
The planting of trees around the mills was also strategic in order to prevent flying debris from accidental explosions.
The incorporating mill buildings were mainly built with timber to reduce the risk of serious harm to millworkers in the event of an explosion, this also enabled repair and reconstruction to occur rapidly if a building was destroyed by a blast.
The hydro power canals covered a distance of 2.5km and for the era, they were a particularly unique feature of the site. The water powered installations were largely powered by breast fed waterwheels with an undershot action, with diameters sometimes as large as 21 feet.
Black gunpowder has three principal constituents; saltpetre (imported from India), sulphur (imported from Sicily), and charcoal, which was the only locally acquired ingredient and was provided by the appropriate forest plantations, using native species such as willow and alder.
Willow was the preferred choice for blasting powders, whilst alder was used for the “sporting powders” – shot gun cartridges and smaller fire arms.
Four pairs of edge runner stones (which were typical crushing apparatus of the time) were situated in each mill and powered by waterwheels. Lammot Du Pont, who was a gunpowder magnate from the USA, travelled to the mills in Ballincollig and noted that the edge runner stones were the largest he had ever seen.
The water turbine at the western carpark has survived in situ. It’s the oldest turbine of any variety to remain intact this way – in Ireland and Britain.
More than 90% of the buildings within the complex have survived in various states of preservation.
Security concerns for the British military were paramount, particularly after the uprising of 1798. This issue was resolved when the army barracks and administrative buildings were built on the Cork/Macroom road in Ballincollig village. This formed part of an enormous military complex during its early years and remains the best preserved industrial site of its type in Europe.
The mills first closed in 1815, however, the initial design and layout of the complex, with some expansion, remains largely the same as the surviving layout which is now immersed in the wood of the park.
There was a second chapter in the story of the Gunpowder Mills between 1833 and 1903. The mills was sold to private ownership for £15,000 and during this period it was the only gunpowder mills in Ireland and the second largest in the former United Kingdom.
In its heyday, 30,000 barrels per annum were shipped from Ballincollig, supplying places as far as Africa, South America and the West Indies, but by 1890, this figure had dropped to 13,000.
This was due to the competitive market place and new emerging explosives that were being engineered elsewhere.
Under British rule, the only thing that kept the mills open towards the very end was the Boer War, which was fought between the British Empire and South African states. Once the war ended in 1902, production ceased by 1903.
The park is free and open to the public. There’s a very helpful app that can be downloaded called ‘Powdermills’, which gives brief descriptions on the functionality and history of each building. The September opening hours are 9am to 8pm.
Next week: Richard Gordon visits Kilcrea Friary.